Why do doctors prescribe birth control pills for an irregular period?

Answer 1

Because Birth Control regulate your period.

In a pack there are either only 21 pills (with hormones)

or 28 pills.... 21 with hormones and 7 placebos ( the placebos are only used to keep the user taking pills every day. Rather than possibly forgetting to start the hormones in 7 days)

Because a pills taken each day this lets you know exactly when your period will occur. *Between 21 and 27 days*

Pills can also decrease a heavy flow, sometimes stopping it ll together.

Some doctors are now prescribing 3 months worth a 7 day break after 3 months, This results in 4 periods pr calendar year.